Sleep apnea is an illness characterized by cessation of breathing during sleep. An apnea episode has been defined as a period of 10 seconds or greater duration of no respiration. See Cartwright, R.D. et al., "The Effects of a Nonsurgical Treatment for Obstructive Sleep Apnea," J. Am. Med. Ass'n 248, p. 705 (1982). After onset of an apnea episode, sleep typically lightens to the point where breathing resumes after 10 to 180 seconds, or the patient may wake up. Patients usually remain unaware of their sleep apneas, even though they may awaken as many as several hundred times each night. Episodes of repeated sleep apneas may take up practically the entire night.
C. F. Samelson, U.S. Pat. Nos. 4,169,473 and 4,304,227, incorporated herein by reference, discloses a device for prevention of obstructive sleep apnea and snoring. When the device is operatively positioned within the mouth, flow of air through the mouth is blocked. A socket within the device engages the tip of a user's tongue, holding the tongue in a forward position. Positive engagement of the tongue in the socket results when the user creates a negative pressure condition within the socket by applying a gentle suction in the socket which operates to hold the tip of the tongue in the socket. The body of the tongue, when so engaged, is held forward of its normal proximity to the soft palate, the uvula and the posterior pharyngeal wall, thereby providing an increase in size of the air passageway through which breathing occurs.
The anti-apnea device described in U.S. Pat. No. 4,304,227 could be expelled from the patient's mouth during sleep, or suction may be lost during sleep, so that the user's tongue slips out of the socket. Protection against sleep apnea and snoring is lost in either event.